Suction lifting device



. Feb. 18, 1930. L. 'M MCCORMICK SUGTION LIFTING DEVICE Filed Nov, 2, 1927 l INVENTOR. 6W HHCLWRMCK TTORNEY.

Patented Feb. 18, 1930 UNITED STATS SUCTION LIFTING DEVICE Application mea November 2, 1927.Y serial No. 230,523.

This invention relates to improvements in suction lifting devices of the kind adapted to draw fluids into containers. p

An object of my invention is to provide an improved suction lifting device having a construction adapted to draw liquids into pipettes with line precision and accuracy.

A further object of my invention is to provide an improved suctionlifting device which y may be operated to draw liquids into pipettes without any danger of contamination or in fection accompaying its use.

A further object of my invention is to provide an improved instrument for drawing speciiic quantities of liquid into containers.

The devices now commonly used to fill pipettes, which are operated by inserting the end of a tube into the mouth, are apt to become contaminated through their Contact with objects or substances not previously sterilized. By means of the present'invention the danger of contamination or infection accompanying the use of pipette illers is practically eliminated, principally because the instrument is not inserted into the mouth of the operator when used.

Other advantages and objects of the present invention will present themselves or will be specifically pointed out in the descrip- 0 tion to follow.

In the accompanying drawings:

Fig. 1 is a side view of a liquid suction device embodying my invention;

Fig. 2 is a longitudinal sectional view of the same taken on the line 2 2 of Fig. 1;

Fig. 3 is a longitudinal sectional view of a fragmentary part of a modified form of liquid suction device embodying my invention;

4G Fig. 4 is a longitudinal sectional view of a fragmentary part of another modified form of liquid suction device embodying my invention showing a means which may be employed with the two plungers for preventing the suction of air through the barel of the device.

Referring to Figs. 1 and 2 of the drawings, the numeral 1 designates a hollow cylindrical shaped barrel having a longitudinally eX- tending slot 2 located in its side, and suitable the said nozzle.

threads at its ends for the attachment of a cap 3 and a nozzle 4.

Movably located inside the barrel 1 is a closely fitting plunger 5 having a small opening 6 extending longitudinally therethrough 55 which registers with the opening located in Movably located inside the opening 6 is a small closely iitting plunger 7 which is adapted to be moved independently of the larger plunger 5. f

Secured to the side of the large plunger 5 at a pointadjacent its end, is a iinger piece 8 which projects through the slot 2 and serves as a means for conveniently moving the said large plunger backwardly and forwardly inside the barrel 1.

The small plunger 7 is secured at its end to a disc member 9 which movably lits within the barrel, and the said disc member is provided with a finger piece 10 which projects through 70 the slot 2 and serves as a means for moving the said small plunger backwardly and forwardly within the small opening 6.

As shown in Fig.4, the plunger 5 may be provided with an encircling band 11, composed of rubber or other suitable material, the said band being adapted to firmly fit against the side of the barrel to prevent the possible suction of air between the walls of the barrel and the circumferential surface of the said plunger. Located adjacent an end of' the plunger 5, inside an enlargement of the small opening 6 and around the small plunger 7, is suitable packing material 12 which may be pressed against the small plunger by a screw S3 13. The screw 18 may be screwed into suitable threads provided in the large plunger` for that purpose, to press the packing material 12 firmly against the small plunger 7 and the walls of the enlarged part of opening 6, and 9o thereby prevent the suction of air through the said small opening.

As shown in Fig. 3, my invention maybe embodied in another form in which the two plungers are positioned in the barrel but apart 93 from each other. In this figure the barrel 1 is shown as having theA nozzle 4 integrally formed therewith, with a longitudinally eX- tending enlargement 14 located on the inside of the said barrel at a side thereof. 'The en- 1Go largement extends part way along the side of the barrel and is provided'with a small longitudinally extending opening 15 within which the small plunger 7 movably fits. A large plunger movably contacts with a side of the barrel andthe inside surface of the enlargement 14, and the end thereof is provided with a disc'lG which contacts with the walls of the said barrel. Attached to the discl is a fingerpiece 8 which projects through the slot, 2 in the said barrel'. l small plunger 7 and provided with the Afinger piece 10, serves as a means for moving` the vsaid plunger baclrwardly and forwardly in the opening l5.

.. The. device herein shown and described is the vdesired amount of this liquid hasbeen thus drawn into n the pipette, the latter is placed in Contact with another body of liquid.v

and the finger piece 8 is moved toward the end of the barrel, thereby carrying with it the larger plunger 5. As the larger plunger 5 is thus moved away from the nozzle 4, a larger stream of fluid is drawn `into the pipette, thereby quickly completing the operation Vof filling the same with the desirable proportions of liquids to be treated or analyzed.

' It is apparent to thoseskilled in theV art that my improved suction device maybe embodied in forms other than those herein shown,so for v this and other apparent reasons I desire my invention included broadly within the spirit of the appended claims.

I-laving` `described my invention, what I claim is: i i v ll, A device of the class described comprisy Y ing a barrel having a slot therein, a -plunger movably located in the barrel and provided Y' with an. opening extending therethrough, a second plunger movably located in the openingin the first mentioned plunger, and separate'flnger piecesextending through the slot in the barrel and attached to the said plungers, whereby the said plungers may be moved independently of each other.

AThe disc 9 attached Ato theV 3. A device of the class described comprising a hollow barrel, a plunger slidably located Y in the barrel having an opening therethrough, a second plunger slidably located inthe opening in the first mentioned plunger, 'separate means associated with each plunger, whereby each plunger may be actuated independently of the other, and means forpreventing the plungers from turning.

Il. A device of the class described comprising a hollow barrel, a plungery slidably located in the barrel for producing a partial vacuum in the barrel, lthe said plunger having an opening therethrough, a second plunger movably located in the opening in the first mentioned plunger for also'producing a partial vacuum in the barrel, means associated with ,each plunger, whereby each plunger may be actuated independently ofthe other, and means y Y Lewis MoN'rFoRD MOooRMIoK.

2. In a device of the class described, the Y.

combination comprising a hollow barrel, a large plunger movably located in the barrel,a

small plunger movably located in the barrel,

separate means vfor *movingv the plungers,

whereby either plunger may be actuated to create a vacuum 1n the barrel, and means for preventing the'plungers from turning. i 

